Greenprint your home workshop: Water and you, what it means to be sustainable for water. Avinash Krishnamurthy of Biome explains the importance of water conservation inside the home - why, what and how.

1. Water and you
What you do makes up the bigger picture

2. How much water do I use ?
Real Consumption range :
from 50 to 300 liters per person per day
National Town planning Norms :
Urban : 135 Lpcd
Rural (Karnataka) : 55 Lpcd
Use
Litres/person
Drinking
3
Cooking
4
How much
Bathing
20
Water do
Flushing
40
YOU
Washing-clothes
25
Washing Utensils
20
Gardening
23
Total
135
Use ?

4. Local hydrologic cycle

5. What about the rain ? : Local hydrologic cycle
Site : 30 * 40 (Area 110 sqm)
Annual rainfall on it in B’lore : 106700 Litres
Before construction
After construction
Runoff : 10%
10670 Litres / annum
Runoff: 80%
85360 Litres / annum
Difference :74690 Litres / annum
Who should manage this excess ?

6. Let’s look at the numbers more closely…..
Rainfall
Water falling on the roof
(30 * 40 site)
10 mm (small shower)
1000 litres
30 mm (Average shower)
3000 litres
60mm (heavy shower)
6000 litres
Annually in Bangalore – 970mm
87300 litres
4 member household, @ 135 lpcd needs 540 litres / day
i.e. in Bangalore there is enough rain falling for 161 days of a family
Or
For nearly 5.5 months of the year
that is
Almost 50% of a household’s needs !!!
Can we capture this store it or recharge it into our borewells
(or can we do rainwater harvesting) ?

8. Most important principles of RWH – 2:
Rainfall pattern & Geology
Bangalore:
MONTH
DAYS
QUANTITY
(mm)
JAN
0.2
2.70
FEB
0.5
7.20
MAR
0.4
4.40
APR
3.0
46.30
MAY
7.0
119.60
JUN
6.4
80.80
JUL
8.3
110.20
AUG
10.0
137.00
SEP
9.3
194.80
OCT
9.0
180.40
NOV
4.0
64.50
DEC
1.7
22.10
TOTAL
59.8
970.00
Rainfall more evenly spread better
for
Direct storage and Use.
Geology and aquifer regime to be
suitable for recharge. Recharge to
be designed for local conditions.
Thumb rule : Open wells good in
deccan plateau. Depth of well
necessary different in different
place. 20ft minimum thumb rule.

9. RAIN WATER HARVESTING FOR HOUSEHOLDS : Quantity, Bangalore
Tank Size Study
300
Days serviced
250
200
150
100
50
0
5000
10000 15000 20000 25000 30000 35000 40000 45000
Tank sizes
Household Rainwater Harvesting:
Plot
size
Area
Sft
in Area
SqM
30x40
1200
111.52
40x60
2400
223.04
In
Runoff for a Runoff
30mm
rain 60mm
(Liters)
(Liters)
for
a
Annual
rain
(Liters)
3,011.15
6,022.30
97,360.59
6,022.30
12,044.61
194,721.19
Runoff

10. Most important principles of RWH – 1:
Catchment and type of harvesting
Direct Storage
& Use
CLEAN CATCHMENTS
STORAGE : SUMPS, RAIN BARRELS (etc)
Recharge
NOT-SO CLEAN CATCHMENTS
RECHARGE : OPEN WELL, DIRECT BOREWELL
RECHARGE, (etc)

11. ….So how clean is Rainwater ?....
A Bucket of Rainwater in
Kurubarakunte village, Bangalore
Rainwater in a Glass
Cauvery water in a Glass
Guess
Which is which ?

12. ….Really as clean as your roof (catchment) is…
Clean Rainwater comes from
Catchments that are clean
– Roof tops are the cleanest Catchment.
Keep your roof clean :
No junking, no pets, no crackers, no holi,
No chemical pesticides/fertilisers on the roof
Managing Rainwater Quality : rainwater picks up contaminants from :
1. Urban pollution – First Rain separation
2. Contamination from the catchment – Catchment management, Pre-filtering
3. Rainwater has low TDS, low Hardness and low all other counts !!!
Rainwater, for drinking will need Point of Use treatment for Bacterial
contamination
Eg: SODIS, Good rolling boil, Aquaguard etc.

13. Site Selection for Infiltration
Many factors affect the suitability of a site as an infiltration facility for the
disposal of stormwater. Among these, the following are most important:
• Depth to groundwater
• Surface soil type
• Underlying soil type
• Vegetation cover of the infiltrating surface
• The uses of the infiltrating surfaces
• The ratio of tributary impervious surface to the infiltrating surface

14. http://www.youtube.com/watch?v=6lVTPhsvp38&feature=channel_page

15. Recharge pit around bore wells

16. The making of a recharge well
Pit and concrete rings
The pit has reach the silt layer
Placing of the rings

17. Recharge wells details
Covers : grilled or
perforated RCC
Silt and leaves trap in a stormwater drain

18. Recharging a bore well
Outlet pipe in recharge well
Rainwater sent for recharge

19. Don’t forget the maintenance

20. Building bye-laws in Bangalore
• ALL buildings with roof area more than 100
square metres
• 20 litres for every sq. mt. (storage or recharge)
• 60 litres for every square metre for more than
5000 square metre plot size

21. Demand – the heart of the scarcity problem
What else can you do?
Reuse Waste Water (eg: Grey for flushing,
Treated black/grey for irrigation)
And use the treated waste water to irrigate
Your roof farm that produces food

22. Water harvesting and grey water reuse in a house

25. Turn sewage to a nutrient through Eco-san